Optical (photonic) networks and the like (e.g., Dense Wavelength Division Multiplexed (DWDM)) are deploying control plane systems and methods. Control planes provide automatic allocation and management of network resources in an end-to-end manner. Example control planes may include Automatically Switched Optical Network (ASON) as defined in ITU-T G.8080/Y.1304, Architecture for the automatically switched optical network (ASON) (February 2005), the contents of which are herein incorporated by reference; Generalized Multi-Protocol Label Switching (GMPLS) Architecture as defined in IETF Request for Comments (RFC): 3945 (October 2004) and the like, the contents of which are herein incorporated by reference; Optical Signaling and Routing Protocol (OSRP) from Ciena Corporation which is an optical signaling and routing protocol similar to PNNI (Private Network-to-Network Interface) and MPLS; or any other type control plane for controlling network elements at multiple layers, and establishing connections therebetween. Control planes are configured to establish end-to-end signaled connections such as Subnetwork Connections (SNCs) in ASON or OSRP, and Label Switched Paths (LSPs) in GMPLS and MPLS.
In addition to control planes which are distributed, a centralized method of control exists with Software Defined Networking (SDN) which utilizes a centralized controller. SDN is an emerging framework which includes a centralized control plane decoupled from the data plane. SDN provides the management of network services through abstraction of lower-level functionality. This is done by decoupling the system that makes decisions about where traffic is sent (the control plane) from the underlying systems that forward traffic to the selected destination (the data plane). Note, distributed control planes can be used in conjunction with centralized controllers in a hybrid deployment. SDN and control planes are configured to compute paths, to route/signal the SNCs/LSPs, and program the underlying hardware accordingly.
Optical (photonic) networks include various Optical Add/Drop Multiplexer (OADM) nodes interconnected by optical links which can include in-line optical amplifiers. An Optical Multiplex Section (OMS) is a network section between two OADMs where spectral loading is constant on all spans. Photonic networks use control planes, SDN, etc. to provide restoration (also referred to as protection) which is a key feature in networks where a backup (protection) path takes over for an active (working) path of a service or call when there is a failure in the active path. Conventionally, photonic services are engineered to operate an associated modulation format which provides a specific amount of bandwidth based on a plurality of factors which determine optical margin based on End of Life (EOL) conditions. With respect to restoration, responsive (or before) a fault affecting a photonic service, a protection path is determined to route the faulted photonic service.
Conventionally, the protection path is constrained to support the margin requirements of the photonic service from its home route (i.e., the originally computed path, the working path). Next-generation optical modems support adaptive bandwidth via adaptable modulation formats and baud rates. These advanced features add complexity to the protection route computation and systems and methods are needed to support unequal bandwidth rates on protection routes while a photonic service is off of its home route.